check if snapshot_count has valid value. closes #540

src/box/lua/snapshot_daemon.lua

@@ -239,6 +239,10 @@ do
             end,
 
             set_snapshot_count = function(snapshot_count)
+                if math.floor(snapshot_count) ~= snapshot_count then
+                    box.error(box.error.PROC_LUA,
+                        "snapshot_count must be integer")
+                end
                 local daemon = box.internal[PREFIX] or daemon
                 log.info("new snapshot count is %s", tostring(snapshot_count))
 

test/box/snapshot_daemon.result

@@ -112,3 +112,7 @@ PERIOD
 ---
 - 0.03
 ...
+box.cfg{ snapshot_count = .2 }
+---
+- error: snapshot_count must be integer
+...

test/box/snapshot_daemon.test.lua

@@ -70,3 +70,5 @@ box.cfg{snapshot_period = 3600 * 4, snapshot_count = 4 }
 space:drop()
 
 PERIOD
+
+box.cfg{ snapshot_count = .2 }